From 979305219eaee3dc7d297f7b3d181988f413cc6d Mon Sep 17 00:00:00 2001
From: Sergey Andreenko <seandree@microsoft.com>
Date: Fri, 16 Feb 2018 09:18:48 -0800
Subject: [PATCH] delete liveness workarond. (#16416)

---
 src/jit/liveness.cpp | 54 +---------------------------------------------------
 1 file changed, 1 insertion(+), 53 deletions(-)

diff --git a/src/jit/liveness.cpp b/src/jit/liveness.cpp
index ba479dc..6793bf5 100644
--- a/src/jit/liveness.cpp
+++ b/src/jit/liveness.cpp
@@ -1977,45 +1977,6 @@ void Compiler::fgComputeLife(VARSET_TP&       life,
     }
 }
 
-static bool HasAnyThrowableNodes(Compiler* compiler, BasicBlock* block, jitstd::vector<GenTree*>& disabledNodes)
-{
-
-    LIR::Range& blockRange  = LIR::AsRange(block);
-    GenTree*    currentNode = blockRange.LastNode();
-    GenTree*    endNode     = blockRange.FirstNonPhiNode()->gtPrev;
-
-    size_t left = disabledNodes.size();
-
-    while (currentNode != endNode)
-    {
-        for (size_t i = 0; i < disabledNodes.size(); ++i)
-        {
-            if (disabledNodes[i] == currentNode)
-            {
-                --left;
-                disabledNodes[i] = nullptr;
-                break;
-            }
-        }
-
-        if (currentNode->OperMayThrow(compiler))
-        {
-            return true;
-        }
-
-        if (left == 0)
-        {
-            return false;
-        }
-
-        currentNode = currentNode->gtPrev;
-    }
-
-    // If we reach here that means that there is an affecting node outside the current block
-    // so return true
-    return true;
-}
-
 void Compiler::fgComputeLifeLIR(VARSET_TP& life, BasicBlock* block, VARSET_VALARG_TP volatileVars)
 {
     // Don't kill volatile vars and vars in scope.
@@ -2045,9 +2006,7 @@ void Compiler::fgComputeLifeLIR(VARSET_TP& life, BasicBlock* block, VARSET_VALAR
                     JITDUMP("Removing dead call:\n");
                     DISPNODE(call);
 
-                    jitstd::vector<GenTree*> disabledNodes(getAllocator());
-
-                    node->VisitOperands([&disabledNodes](GenTree* operand) -> GenTree::VisitResult {
+                    node->VisitOperands([](GenTree* operand) -> GenTree::VisitResult {
                         if (operand->IsValue())
                         {
                             operand->SetUnusedValue();
@@ -2057,9 +2016,6 @@ void Compiler::fgComputeLifeLIR(VARSET_TP& life, BasicBlock* block, VARSET_VALAR
                         // these nodes.
                         if (operand->OperIs(GT_PUTARG_STK))
                         {
-
-                            // collect stack-affecting nodes
-                            disabledNodes.push_back(operand);
                             operand->AsPutArgStk()->gtOp1->SetUnusedValue();
                             operand->gtBashToNOP();
                         }
@@ -2067,14 +2023,6 @@ void Compiler::fgComputeLifeLIR(VARSET_TP& life, BasicBlock* block, VARSET_VALAR
                         return GenTree::VisitResult::Continue;
                     });
 
-                    if (!disabledNodes.empty())
-                    {
-                        if (HasAnyThrowableNodes(this, block, disabledNodes))
-                        {
-                            codeGen->setFramePointerRequired(true);
-                        }
-                    }
-
                     blockRange.Remove(node);
 
                     // Removing a call does not affect liveness unless it is a tail call in a nethod with P/Invokes or
-- 
2.7.4